I’ve made a Cursed USB-C 2.0 device • Hacker News Board

Re: I’ve made a Cursed USB-C 2.0 device

#101

Post by duskwuff » Mon, Mar 22, 2021, 5:25 PM UTC

buran77 wrote: post #80

chaorace wrote: post #50

Earlier quoted context omitted.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

A standard USB 3.1 type A connector has 9 pins. The reversible type C has 3 extra pins (SBU, CC, VBUS), not counting the doubling caused by making it reversible. So while the reversibility doubled the number of pins, the increased complexity of the standard itself tripled it (from 4 to 12).

> A standard USB 3.1 type A connector has 9 pins. The reversible type C has 3 extra pins (SBU, CC, VBUS)

Not precisely. The type C connector has four distinct USBSS pairs; the type A connector only has two. This allows the type C connector to be used to carry DisplayPort or other high-speed data alongside USB.

Re: I’ve made a Cursed USB-C 2.0 device

#102

Post by gpderetta » Mon, Mar 22, 2021, 5:29 PM UTC

rand49an wrote: post #29

Tade0 wrote: post #18

My Galaxy S8 and 60W USB-C charger appear to work like this - I often have to do a 180° turn for the phone to start charging. They only do that in this combination. Not sure if it's consistent though - I should probably mark one side and check.

My Nokia phone is the same, it's a broken port I think.

same for my Motorola. It will only charge one one side. The best part is that if plugged in on the "wrong side". It is great when it runs out of batteries and you have to gamble that you plugged it in correctly.

Re: I’ve made a Cursed USB-C 2.0 device

#103

Post by pinkythepig » Mon, Mar 22, 2021, 5:31 PM UTC

legohead wrote: post #92

Hnaomyiph wrote: post #4

I feel like USB-C is cursed enough on its own. The sheer number of times I’ve had to explain to family members why just because the two USB-C ports on a laptop look the same, doesn’t mean they work the same.

I've had more issues with USB-C connections wearing out than other formats, even micro&mini-usb. My phone barely charges at this point, which is frustrating because it otherwise performs fine. I'm going to have to buy a new phone because of the damn charging port! I was considering how many times I've actually plugged it in. Worst case for me would be 3x/day. At 3 years, that's only ~3300 times. Surely they stress te…

my phone had an issue with charging cables falling out. Turns out the port had compacted lint jammed in it. Turned the phone off and used a needle to clean it all out, phone retains cables now like the day it was new.

Re: I’ve made a Cursed USB-C 2.0 device

#104

Post by mauvehaus » Mon, Mar 22, 2021, 5:35 PM UTC

mindslight wrote: post #76

mauvehaus wrote: post #36

Earlier quoted context omitted.

There are actually different connectors for 15 and 20 amp devices in the US under NEMA. You do see NEMA 5-15R receptacles on 20A circuits in residential applications, but that's probably because most appliances don't require 20 amps. A 5-15 connector has two vertical prongs, a 5-20 has a horizontal and a vertical, with the special case of receptacles with a T slot that fits both 5-15 and 5-20 plugs. It goes a bit dee…

safety nit: By using a dryer circuit (30A), you've got the wrong overcurrent protection on the saw. Which means that some failure modes could overload the saw, but not trip the breaker. The proper ways to do this is to run a new 20A 240V circuit, or to incorporate a subpanel with a 20A breaker into your extension cord. I don't think the risk is severe [0], but you should at least know your setup goes against the elec…

You raise a couple points I point I hadn't considered.

Rewiring the motor to 115v is probably a no-go, since it's a 3hp motor (continuous), which I believe is more amps at 120v than could be drawn from a normal circuit.

For safety, I'm wondering what kind of faults wouldn't be protected against. The starter has built-in thermal protection (heaters), which should protect the motor from the unlikely use case where I'm pushing the saw too hard, or more likely, a stall on start-up.

The breaker should still protect against shorts. I'm not knowledgeable enough to know what other faults could lead to an over current fault that one or the other of those wouldn't catch.

Would anybody care to educate me?

Also: the most dangerous aspect of a table saw is probably not the potential for electrical faults :-)

Re: I’ve made a Cursed USB-C 2.0 device

#105

Post by Yizahi » Mon, Mar 22, 2021, 5:36 PM UTC

protomyth wrote: post #63

weinzierl wrote: post #16

Now I want a USB-C thumb drive that has different data on different sides. Like the old 5 1/4" diskette drives where you flipped the disk for double capacity. Using it for retro-gaming would be fun. When the game says "Flip the Disk" you flip the USB drive.

The 007 version would have data on one side and blank the drive if plugged in the wrong way or, well, blow up to provide a distraction.

And sides would be completely unlabeled...

Re: I’ve made a Cursed USB-C 2.0 device

#106

Post by StavrosK » Mon, Mar 22, 2021, 5:38 PM UTC

I have devices (two, IIRC) that only charge if they're connected in one orientation and not the other. So frustrating.

Re: I’ve made a Cursed USB-C 2.0 device

#107

Post by mauvehaus » Mon, Mar 22, 2021, 5:41 PM UTC

sneak wrote: post #41

mauvehaus wrote: post #36

Earlier quoted context omitted.

There are actually different connectors for 15 and 20 amp devices in the US under NEMA. You do see NEMA 5-15R receptacles on 20A circuits in residential applications, but that's probably because most appliances don't require 20 amps. A 5-15 connector has two vertical prongs, a 5-20 has a horizontal and a vertical, with the special case of receptacles with a T slot that fits both 5-15 and 5-20 plugs. It goes a bit dee…

> You do see NEMA 5-15R receptacles on 20A circuits in residential applications This is, of course, what I was talking about. I do appreciate the nuances of the 15/20 T-socket and the 6-20/5-20 symmetry; NEMA is super cool (aside from the fact that bladed plugs that aren't twist-lock are sort of lame/less safe in general, at least compared to the UK standard bladed plug). It's a fun rabbit hole to venture down: my oc…

That's never bothered me, but I guess I see your point. I always figured that the point of having a 20A circuit with 15A receptacles was so that you can plug in and run two 10A devices without popping the breaker.

Stupid question: are there any common household appliances that draw 20A? I've only ever seen the T receptacles in non-household uses.

Re: I’ve made a Cursed USB-C 2.0 device

#108

Post by MivLives » Mon, Mar 22, 2021, 5:53 PM UTC

gregmac wrote: post #71

avian wrote: post #48

Earlier quoted context omitted.

I find it funny how people used to complain about the sheer number of times they had to explain to family members exactly the opposite: "No need to ask. If you can plug it in, then it will work. Computers are fool-proof like that. No, it's not like the jacks on the hi-fi" As in, someone got a new mouse and didn't know where to plug it into their computer, when in fact there was only one DB-9 connector on the computer…

I think this was at its peak when basically every computer had only USB 2.0 ports. You pretty much could plug in anything to anything, so long as it fit. Not to say there were no issues -- USB 1.1 hubs, cable length limits -- but they were so incredibly minor compared to today. USB 3 introduced blue plugs, complicating things slightly but still everything basically worked, and if something was operating slower than e…

I don't understand why the color coding plugs wasn't brought back for C. The 3.0 vs 2.0 thing was nice, and made it easy to tell what I needed to plug into. Now I have a phone with a 2.0, a laptop with a 3.1, and a macbook with a thunderbold, and my USB to HDMI port only works with one of the three.

Re: I’ve made a Cursed USB-C 2.0 device

#109

Post by NelsonMinar » Mon, Mar 22, 2021, 5:55 PM UTC

I have this problem in practice plugging my Pixel 5 phone into my car for Android Auto. The cable only works in one orientation. Android Auto is notorious for being very finicky about connections; no one's really figured it out but it seems to work better with shorter cables and of course higher quality cables. I've assumed my particular problem was some quirk of the connector fit, but now I'm wondering if it could be related to the asymmetry in the data pin design.

Re: I’ve made a Cursed USB-C 2.0 device

#110

Post by williamscales » Mon, Mar 22, 2021, 6:01 PM UTC

danielEM wrote: post #44

USB, HDMI, Cable ethernet, DisplayPort, PCIe, ... they all use differential signals to transmit data, just different protocols. We could really and truly have just one type of plug to connect everything to everything a long time ago and without proprietary licenses. As much as I like what USB-C offers as much I hate it and other "stupid" standards that duplicate same function just with differnt plugs - transfering da…

I've asked a lot of hardware engineers why ethernet is not simply used for everything.

I've never gotten a real answer, one that involves technical reasons. It could be done, but it isn't.

I guess people like having different kinds of cables?